Question

How do I use the awk range pattern '/begin regex/,/end regex/' within a self-contained awk script?

To clarify, given program csv.awk:

#!/usr/bin/awk -f

BEGIN {
FS = "\"" 
}

/TREE/,/^$/
{
  line="";
        for (i=1; i<=NF; i++) {
                if (i != 2) line=line $i;
        }

        split(line, v, ",");
        if (v[5] ~ "FOAM") {
                print NR, v[5];
        }
}

and file chunk:

TREE
10362900,A,INSTL - SEAL,Revise
,10362901,A,ASSY / DETAIL - PANEL,Revise
,,-203,ASSY - PANEL,Qty -,Add
,,,-309,PANEL,Qty 1,Add
,,,,"FABRICATE FROM TEKLAM NE1G1-02-250 PER TPS-CN-500, TYPE A"
,,,-311,PANEL,Qty 1,Add
,,,,"FABRICATE FROM TEKLAM NE1G1-02-750 PER TPS-CN-500, TYPE A"
,,,-313,FOAM SEAL,1.00 X 20.21 X .50 THK,Qty 1,Add
,,,,"BMS1-68, GRADE B, FORM II, COLOR BAC706 (BLACK)"
,,,-315,FOAM SEAL,1.50 X 8.00 X .25 THK,Qty 1,Add
,,,,"BMS1-68, GRADE B, FORM II, COLOR BAC706 (BLACK)"
,PN HERE,Dual Lock,Add
,
10442900,IR,INSTL - SEAL,Update (not released)
,10362901,A,ASSY / DETAIL - PANEL,Revise
,PN HERE,Dual Lock,Add

I want to have this output:

27 FOAM SEAL
29 FOAM SEAL

What is the syntax for adding the command line form '/begin regex/,/end regex/' to the script to operate on those lines only? All my attempts lead to syntax errors and googling only gives me the cli form.

Answer 1

Simply do:

#!/usr/bin/awk -f

BEGIN {
FS = "\"" 
}

/from/,/to/ {
  line="";
        for (i=1; i<=NF; i++) {
                if (i != 2) line=line $i;
        }

        split(line, v, ",");
        if (v[5] ~ "FOAM") {
                print NR, v[5];
        }
}

If the from to regexes are dynamic:

#!/usr/bin/awk -f

BEGIN {
    FS = "\"" 
    FROM=ARGV[1]
    TO=ARGV[2]
    if (ARGC == 4) { # the pattern was the only thing, so force read from standard input                   
       ARGV[1] = "-"
    } else {
       ARGV[1] = ARGV[3] 
    }
}

{ if ($0 ~ FROM) { p = 1 ; l = 0} }
{ if ($0 ~ TO)   { p = 0 ; l = 1} } 

{  
  if (p == 1 || l == 1) {
   line="";
        for (i=1; i<=NF; i++) {
                if (i != 2) line=line $i;
        }

        split(line, v, ",");
        if (v[5] ~ "FOAM") {
                print NR, v[5];
        }
   l = 0 } 
}

Now you have to call it like: ./scriptname.awk "FROM_REGEX" "TO_REGEX" INPUTFILE. The last param is optional, if missing STDIN can be used.

HTH